RS-485,RS-232,RS-422区别和理解 目录概述需求: 设计思路实现思路分析1.概述2.区别 参考资料和推荐阅读 Survive by day and develop by night. talk for import biz , show your perfect code,full busy,skip hardness,make a b…
一、报错信息:hive> show databases;FAILED: HiveException java.lang.RuntimeException: Unable to instantiate org.apache.hadoop.hive.ql.metadata.SessionHiveMetaStoreClient 解决办法:1.删除mysql中的元数据库(metastore࿰…
要授予用户帐户权限,可以用GRANT命令。有撤销用户的权限,可以用REVOKE命令。这里以 MySQl 为例,介绍权限控制实际应用。
GRANT授予权限语法:
GRANT privilege,[privilege],.. ON privilege_level
TO user [IDENTIFIED BY passwo…